they may consider it offensive. and in that case they just recommend that you block that person. >> i don't want to minimise this, because i mean, there's some really horrible things that are on line, and it's not - it's not just twitter, what has happened through social media and the anonymity of the net is that you see websites, hate-filled websites targetting all sorts of groups, popping up. there has been a huge number of those that exist as well. (vo) friday night ... >> does the nsa collect any type of data on millions of americans? >> no sir. (vo) fault lines investigates what it's like to live under the watchful eye of the nsa. >> they know everything that you do, everything that you think, everything that you fear. they know how to manipulate and control you. the state has all the power.